(1) Field of the Invention
The invention relates to a signal unit for signaling at least one operating state of a technical device such as a machine, installation, vehicle, or the like, having at least one acoustic signal transmitter for generating an acoustic signal. More particularly the invention pertains to a sensing unit for detecting an acknowledgment of the signal.
(2) Description of Related Art Including Information Disclosed Under 37 C.F.R. 1.97 and 1.98
Signal devices are frequently used for signaling operating states of technical devices such as machines, installations, vehicles, or the like. These devices are used, among other purposes, to acoustically and/or optically signal malfunctions of such machines or installations in such a way that the operator is able to recognize and remedy this problem. Such signal devices may also signal operating states that represent hazards for the surroundings or for persons in the surroundings.
Machines or installations are often operated continuously to achieve full capacity utilization. In many manufacturing operations, such machines run essentially automatically, thus requiring few operating and monitoring personnel. The occasional inability to monitor individual machines or installations is unavoidable, and can result in unidentified malfunctions with associated adverse accompanying effects, such as a shutdown, for example, or possibly even leading to hazardous situations.
When an operator perceives the signal or alarm, in many cases the technical device is stopped or the power supply to the technical device is cut off by use of a switch such as an emergency stop switch or the like. The operator then remedies the malfunction and turns the technical device back on or restores the power supply.